Seats



June 25, 1968 F. DRABERT 3,339,936

SEATS Filed Nov. 18, 1966 2 Sheets-Sheet l Drenfir' Frlij brd bet-l.

June 25, 1968 F. DRABERT 3,389,936

SEATS Filed Nov. 18, 1966 2 Sheets-$heet 2 FIG. 7.

United States Patent 3,389,936 SEATS E-itz Drabert, 37 Marienstrasse,Minden, Westphalia, Germany Filed Nov. 18, 1966, Ser. No. 595,508 Claimspriority, application Germany, Apr. 30, 1966, D 33,365 5 Claims. (Cl.297459) ABSTRACT OF THE DISCLOSURE A seat comprising a rear portion witha depression and having a rearmost portion adjacent to the rear of thedepression which rises in a smooth curve to the rear edge of the seat.Side portions of the seat are disposed adjacent to and laterally of thedepression and each side portion rises in a smooth curve to therespective lateral edge of the seat. The seat further has a flat portionat the front and the side portions each slope upwards towards the frontportion, the slope decreasing gradually to nil where the side portionsmeet the front fiat portion.

This invention relates to seats.

Various existing chair bottoms have a shaped seat which forms awedge-shaped surface, straight or curved, rising towards the rear, toserve as a support for the pelvis of the person using it.

Medical investigations and practical experience have shown thelimitations of chair bottoms shaped in this way. In the case of thechair bottom having a wedge-shaped seat rising towards the rear,emphasising the sacro-etfect, the disadvantage is a too pronouncedcentering of the buttocks of whoever uses a seat so shaped. Thisdrawback is the more marked where there is further shaping at the front,to provide the desired leg attitude, so that sitting under constraint isno exaggeration as a description of this; for it is a principle ofseating technique that even the most restful support is unbearable inthe long run, if no change of posture is possible.

There is, too, no longer any novelty about seats in which thisconstraining shape is avoided by the absence of any centering, in theform of a prescribed seat moulding or leg shaping, additional to thewedge-like rise of the rear part of the seat. The disadvantage of theseproposed seats is that the muscles around the tuber ischii aresubjected, on such a plane seat, to increased specific pressure.

It is an object of the invention to provide an improved seat.

According to the present invention there is provided in a seat, a rearportion having a depression therein, a rearmost portion adjacent to therear of the depression and rising in a gentle curve to the rear edge ofthe seat, side portions adjacent to and laterally of the depression,each said side portion rising in a gentle curve to the re spectivelateral edge of the seat, and a front flat portion of the seat, the sideportions each having a slope upwards towards the front portion whichdecreases gradually to nil where the side portions meet the front flatportion. That portion of the seat which is right in front, i.e. thefrontmost portion and which extends from the absolutely horizontal orfiat portion towards the front edge and the two side edges may have theshape of a double trapezium with a common base line.

One example of a chair seat embodying the invention will now bedescribed, by way of example, with reference to the accompanyingdiagrammatic drawings, in which:

FIGURE 1 is a perspective view of a seat in accordance with theinvention;

FIGURE 2 is a longitudinal section along the line I-I in FIGURE 1;

3,389,936 Patented June 25, 1968 "ice FIGURES 3 to 7 are cross-sectionsalong the lines IIII, III-III, IVIV, V-V and V'I-VI in FIGURE 2; and

FIGURE 8 is a perspective view of another embodiment, the periphery ofwhich differs somewhat from that shown in FIGURE 1.

The chair bottom here proposed has a seat which is made, moreparticularly, of some material which retains its shape, plywood orplastics being prime examples. What is aimed at is the provision of agood posture, resulting from the shape of the seat surface hereproposed.

As can be seen from FIGURES 1 to 8, the rear portion of the seatcontains a depression 7, to accommodate the users tuber ischii. Runningrearwards from this depression, across the entire width of the seat, ispart 1 of the seat, which curves gently upwards, with a wedge effect, tothe rear edge 2 of the seat. This part 1 of the seat, curving gentlyupwards towards the rear with a wedge effect, affords particularlyeffective and suitable support all around to the users pelvis, so thatthe specific pressure on the muscles has the most favourable possiblevalue.

Portions 4 of the seat, adjacent one each side of depression 7, curvegently upwards to side edges 3 of the seat, the upward slope of theseside portions 4 towards the front of the seat gradually dropping to nilin the absolutely horizontal region 5, of the front part of the seat.This feature gives freedom of side movement to the users thighs. Region5 of the front part of the seat is not curved or shaped in any wayacross the seat.

The very front portion of frontmost portion 6 of the seat curvesdownwards, from region 5 towards the front edge and the two side edges 3of the seat, to avoid the pressure of a hard edge on the thighs.

This novel seat design is medically acknowledged to offer the bestseating characteristics.

A person sitting for long periods at a time is completely free to alterhis posture. He can avoid the wedge effect and sit back, which meansthat he can avail himself of any desired change in the position of thechairback to shift the surface pressure. He can use the chairback totake his weight and support his body, without needing to dispense with ashaped seat having the advantage of reducing pressure on the musclesround the tuber ischii. Exaggeration of the lumbar curve of the spinalcolumn, which results from excessive strain on the small vertebraljoints, due to this wedge effect, is substantially eliminated.

The seat described has the advantage that the chair seat enables theuser to sit back and avoids the wedge effect, in addition to which theusers pelvis is not brought into an unnatural shape.

I claim:

1. In a seat,

a rear portion having a depression therein,

a rearmost portion adjacent to the rear of the depression and rising ina gentle curve to the rear edge of the seat,

side portions adjacent to and laterally of the depression, each saidside portion rising in a gentle curve to the respective lateral edge ofthe seat, and

a front fiat portion of the seat, the side portions each having a slopeupwards towards the front portion which decreases gradually to nil wherethe side portions meet the front flat portion.

2. In a seat according to claim 1,

a frontmost portion extending between the front fiat portion and thefront edge of the seat, said frontmost portion curving downwardly to thefront edge.

3. A seat according to claim 1, wherein the periphery of the seat, whenprojected, has the shape of a double trapezium with a common base line.

3 4 4. A seat according to claim 1, wherein the seat is made FOREIGNPATENTS of shape-retaining material.

5. A chair incorporating the seat of claim 1. 1,159,038 6/1958 France.

563,897 1/1957 Italy. References Clted 5 372,331 4/1953 Germany.

UNITED STATES PATENTS 3,133404 6/1964 Newton 297 23 CASMIR A. NUNBERG,Primary Examiner.

3,177,036 4/1965 Halter 297454

